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Methods

This site provides information on the numbers of birds ringed and the reports (recoveries) of ringed birds received for the whole Ringing Scheme covering Britain and Ireland as well as for each of the five countries and the individual counties. Information is included on birds reported during the year. Counties are currently based on old (1970s) boundaries for technical reasons, but we will change them as soon as we are able.

Ringing and Recovery Totals

Totals of the number of birds ringed and recovered in the year are given. For each species the number ringed are classified by age-classes. Pulli are birds ringed in the nest, juveniles are those identified as being in their first calendar year, adults are all birds in their second or later calendar year. Some birds cannot be aged by plumage characteristics, these unaged birds are tabulated separately and included in the totals for the year.

Totals of the number of birds recovered, that is reported dead or alive to BTO HQ, during the year are given. This includes all recoveries received by the end of April of the next year that relate to the report year. For full details on what constitutes a recovery see below, but this generally includes birds that have been found dead, or that have been reported alive more than 5 km from the original site of ringing. For details of the individual recoveries click on the ‘more’ link at the end of each line; this link is only included where there are recoveries in the current year.

Only those species on the British List (categories A, B, C) are included, with the exception of Eagle Owl (Bubo bubo, category E). This species is included because more than 20 pulli of birds breeding in the wild have been ringed, allowing us to monitor the population. Note that common and scientific names, and the taxonomic order, are as recommended by the British Ornithologists’ Union (BOU) at the time the tables were generated.

British Birds Rarities Committee (BBRC) and Irish Rare Birds Committee (IRBC) rarities reported by ringers are included in this list but adjustments may be made later if any individuals are not accepted. Eagle Owl is currently on category E of the BOU list and not all records have been assessed.

Summary table of the five counties ringing the greatest number of each species in the year. The number ringed in each county is given (in parentheses), together with the total number ringed in the year. Note: the ringing totals for 2009 or earlier only include birds for which the ringing data were submitted electronically. From 2010 all ringed birds have been computerised and are included.

Summary table of the five most ringed species for each county in the year. The number ringed in each county is given (in parentheses), together with the total number ringed in the year. Note: the ringing totals for 2009 or earlier only include birds for which the ringing data were submitted electronically. From 2010 all ringed birds have been computerised and are included.

Recoveries

For each species the following information is included:

Tables:

Species name and scientific name (and link to relevant BirdFacts page which contains additional information on population status, trend and ecology).

Summary of all movements within Britain & Ireland: short (less than 10km), medium (10-99 km) and long (100 km +). In each case the figure before the / is the total for the current year, while the figure after the / is the grand total (1909 to the current year).

Summary table of international movements. The main table summarises movements between Britain & Ireland and much of Europe, covering the countries with which there are most exchanges (see list). The top line of the table (BTO ringed) shows the number of recoveries of BTO-ringed birds reported abroad (ie outside Britain & Ireland) in the current year. The second line shows the grand total (Total BTO) of recoveries of birds ringed in Britain & Ireland that have been reported abroad. The third line (From Abroad) shows the number of recoveries of foreign-ringed birds reported in Britain & Ireland in the current year and the bottom line (Total Abroad) shows the grand total of foreign-ringed birds reported here. Movements to and from other countries are summarised in the lines below the tables. As in the table, the figures in brackets are the number of recoveries reported in the year followed by the total to or from that country separated by a /. If there are no overseas movements then this table is omitted. Note: in all cases the number given is the number of recovery reports rather than the number of individuals; for a few species (particuarly those with large colour-ringng programs), the number of reports may be substantially greater than the number of individuals.

IMPORTANT: please note that at present the grand totals of foreign-ringed birds are incomplete as for some species only those from 1979 onwards have been computerised. We are currently computerising the older foreign recoveries and will update the tables when they have been completed. Please note that this is a big job and will not be finished for some time to come.

Recoveries:

Each recovery is in two lines (ringing information and finding information) and includes the following details:

Line 1:

Ring number or scheme code. Ring number is on first line for all BTO-ringed birds and second line for all foreign-ringed birds. For foreign-ringed birds the scheme code is given on the first line.

Age (and sex where known) when the bird was ringed. If sex was not known when the bird was ringed, sex given on finding is included here.

Date of ringing.

Place the bird was ringed, with geographical coordinates, county (in brackets), country (in bold) where it is not Britain & Ireland.

Line 2:

What happened to the bird.

Date of finding. If an accurate date is not known then a c is placed before it.

Place the bird was found (as above) and

the distance and direction moved.

Finding date:note that some recoveries will have finding dates in earlier years as, although they were found in the year shown, they were not reported until the current year.

Confidential sites: for sensitive species, ringing co-ordinates may be given that are deliberately inaccurate by up to 5km (these are indicated by a 'c.' preceding the lat/long), or not given at all. In these cases, a county will be indicated; in a few extreme cases, the location may be shifted to a neighbouring county.

Incomplete ring numbers:where a full ring number is not known, the missing digits are indicated by ‘_’.

Selections included:

Oldest birds reported in the year. A list of the oldest records of ringed birds reported in the year (time between ringing and finding). A maximum of five records are listed and an individual will be included only once, even if it was reported multiple times during the year. No reports of less than a years duration are included and recoveries are listed in descending order of duration between ringing and finding. The longevity record for birds of this species ringed in Britain & Ireland is given at the top of this section where there is also a link to the full record. Longevities of less than three years are not shown. If there are no records of five or more years, a note is included to this effect and the national longevity figure given. IMPORTANT: Longevity is simply the length of time a bird has been carrying a ring, if the bird was initially ringed while an adult, its actual age may be much older. A few birds for which the finding date is uncertain are excluded.

Longest movements reported in the year. A list of the longest movements within Britain and Ireland of ringed birds reported in the year. Only those over 100 km are included and a maximum of five recoveries is shown, listed in descending order of distance moved. If an individual is reported more than once during the year, only the recovery of the greatest distance will appear. If there are no records exceeding 100 km, this section will not appear.

Birds ringed in Britain & Ireland and reported abroad during the year. A list of birds ringed in Britain & Ireland and reported abroad during the year. Only those where there have previously been 20 or fewer recoveries for that species in that country are shown. An individual bird may appear multiple times if it is reported from several locations or on different dates.

Birds ringed abroad and reported in Britain & Ireland during the year. A list of birds ringed abroad and reported in Britain & Ireland during the year. Only those where there have previously been 20 or fewer recoveries for that species from that country are shown. An individual bird may appear multiple times if it is reported from several locations or on different dates.

Throughout foreign schemes are referred to by a three letter code, with the first two letters indicating the country and the third the city in which the ringing scheme operates. The commonest are listed here:

Species with few recoveries. If there have been fewer than 100 recoveries of a species from BTO ringing, or fewer than 10 recoveries involving the county, then details of all recoveries are given unless these have already been listed because of their longevity, distance moved or because they moved to or from a country with few such recoveries.

Maps. For birds that have moved more than 20 km a link is provided to a map showing ringing and finding locations. Ringing location is marked by a blue (R), finding locations are numbered in sequence, if there are more than ten finding locations, subequent markers will be labelled (x). Finding markers are coloured red for birds found dead and green for birds seen alive, for those where this is not known the marker will be white. NOTE: If a bird is found multiple times at the same site only one marker will be visible.

Further details

Recoveries

Recoveries are reports of birds found dead and those found alive away from the site of ringing. For most species, reports of live birds recaught by ringers within 5 km of the ringing site are classified as retraps and are not processed as recoveries. For some species, special criteria for classification as recoveries are used These are listed below. In addition, a few local retraps of particularly long-lived birds are added to the national recovery files each year. Since 2005, ringers have submitted all retraps, either electronically or on paper. Electronic reports are stored on an ORACLE database at BTO HQ. Prior to 2005 many retraps were reported electronically and these are also on the HQ database; however, these data are not complete.

Storm Petrel: All movements over 20 km are processed, as well as movements of 5 km or more for birds that are likely to be breeding. Breeders are defined as birds retrapped four or more years after being ringed as chicks or juveniles, or three or more years after ringing as adults.

Mute Swan & Canada Goose: Sightings and rehandlings over 40 km are all processed. Movements between 5 km and 40 km are included if considered significant by the ringer.

Gulls: The threshold distance moved for Black-headed, Lesser Black-backed, Herring, Great Black-backed and Common Gull is 40 km. For all other species the threshold is 5 km.

Sand Martin: The minimum distance for a control to be processed is 10 km.

For listing in the longevity section of the recoveries table a report is excluded if the finding condition (see below) is coded as 3 (ie not freshly dead) or if the accuracy of the finding date is uncertain.

Age

Birds ages are recorded on a calendar year basis, using standard codes devised by Euring which can be found by clicking here. For the avoidance of doubt, ages in the totals and recovery tables are defined in terms of these codes as follow:

Totals Table: Pulli are birds aged as 1 or 1J (ie birds ringed in the nest or close to the nest and only able to fly weakly), Juveniles are birds aged as 3 or 3J (ie birds known to have hatched in the current calendar year), all other birds are regarded as adult except those where the age is recorded as 0 (ie no details), 2, or 4 in the period January-April (ie full-grown, but year of hatching unknown), which are considered unaged.

Recoveries: Nestling refers to birds aged as 1 or 1J, ie pulli. Juvenile to a full-grown bird with mostly juvenile feathers (codes: 2J and 3J), this applies to passerines only. First-year birds are those in their first actual (not calendar) year of life (codes: 3 and 5 if the bird was ringed between January and April). Second-year birds are in their second year of life (Codes: 5 if ringed in May or later and 7 if ringed between January and April), note this applies mostly to non-passerines. All other birds are considered Adult, except those aged as 2 (or 4 in January through April), these birds are listed as Full Grown since their year of hatching is unknown.

Finding Circumstances

As with age codes Euring provides a standard set of codes to classify the circumstances in which the bird was found. These can be found by clicking here. Two codes are used one detailing the finding condition (dead, long dead, alive etc) and one the finding circumstance (eg taken by predator, caught by another ringer). The descriptions provided here represent a simplified interpretation of these codes as follows:

Finding Condition

Description

Code

Dead

1

Freshly Dead

2, 21*, 22*

Long Dead

3 (ie dead for more than about a week)

Sick

4,5

Field Sighting

79*, 89*

Alive

6, 7, 8, 9 (but see next two)

Caught by ringer

8 (and circumstance code 20)

Caught in nestbox

8 (and circumstance code 27)

Unknown

0

* Note these are BTO specific codes, so don’t appear in the Euring exchange code.

The BTO Ringing Scheme is funded by a partnership of the British Trust for Ornithology, the Joint Nature Conservation Committee (on behalf of: Natural England, Natural Resources Wales and Scottish Natural Heritage and the Department of Agriculture, Environment and Rural Affairs, Northern Ireland, The National Parks and Wildlife Service (Ireland) and the ringers themselves.